Dairy Day, 1988
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Item Open Access Cause and control of hydrolytic rancidity in raw milk(Kansas Agricultural Experiment Station, 2012-09-20) Jeon, I.J.One of the common and important off-flavors in milk is hydrolytic rancidity or lipolyzed flavor. The rancidity results from hydrolytic cleavage of fatty acids from milk fat by the enzyme lipase and their release as free acids. The release of these acids in milk, even in very small amounts, imparts a bitter taste and a sharp, unpleasant aroma. The off-flavor is often described as "goaty", "butyric", "soapy", and "bitter" The term "bitter", however, is ambiguous because bitter flavors can occur from the result of protein breakdowns. Nevertheless, both farm and dairy plant problems may lead to its development. Once an objectionable level is reached, no processing technique will eliminate it.Item Open Access Errors in heat detection are costly(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; jssAttention to heat detection will decrease reproduction losses and costs associated with extended calving intervals and high culling rates. Errors in diagnosing heat (errors of commission) and missed heats (errors of omission) are the major errors of a heat detection program. Priority must be given to heat detection to improve reproductive efficiency and reduce the costs of reproductive failure on dairy farms.Item Open Access Nutrient requirements of dairy cattle revised(Kansas Agricultural Experiment Station, 2012-09-20) Dunham, James R.The 1988 National Research Council's (NRC) Nutrient Requirements of Dairy Cattle have been revised. Adjustments have been made in the recommended requirements for net energy for lactation (NEL); crude protein (CP); calcium (Ca); phosphorus (P); and vitamins A, D, and E. In addition, suggestions are made for using undegraded intake protein (UIP) and degraded intake protein (DIP) for diet formulation.Item Open Access Effects of production on reproductive traits in Kansas Holstein herds(Kansas Agricultural Experiment Station, 2012-09-20) Call, Edward P.The analysis of dairy herds to evaluate the reported negative effect of production on reproduction failed to identify a real relationship. Higher-producing herds excel in all areas of reproductive performance, except conception rate. Of greatest importance is the annual reproductive loss that is affected by the reproductive traits measured. As production per cow increased, the yearly dollar loss per cow declined from a high of $163 to $73 yearly in the group averaging 20,118 lb milk.Item Open Access Small intestinal starch, dextrin, and glucose digestion in steers(Kansas Agricultural Experiment Station, 2012-09-20) Kreikmeier, K.K.; Harmon, D.L.; Avery, T.B.; Brandt, Robert T., Jr.Three Holstein steers (930 lb) were surgically fitted with abomasal and ileal cannulae, portal and mesenteric venous catheters, and an elevated carotid artery and used to study small intestinal starch digestion. Water, corn starch (66 g/hr), corn dextrin (66 g/hr), or glucose (66 g/hr) were continuously infused into the abomasum. Small intestinal disappearance of corn dextrin (57 g/hr) and glucose (57 g/hr) were higher (P<.05) than that of starch (48 g/hr). The percentage of carbohydrate disappearance accounted for as net portal glucose flux was 52, 54, and 72% for corn starch, corn dextrin, and glucose, respectively. Small intestinal starch utilization in the bovine may be limited by starch granular characteristics, enzyme activity, and glucose transport across the small intestine.Item Open Access The evaluation of rapid methods for monitoring free fatty acid levels in cheese(Kansas Agricultural Experiment Station, 2012-09-20) Ikins, W.G.; Kwak, H.S.; Zink, G.S.; Jeon, I.J.The amount of free fatty acids present in cheese is important to dairy processors because these compounds make a significant contribution to the overall flavor. In this study, the results obtained using three relatively rapid methods of determining free fatty acids concentrations in cheese were compared to those acquired by using a more laborious but accurate gas chromatographic technique. One method, the Extraction-Titration Method, was found to be superior to the others because of its simplicity and reliability. In addition, the values obtained by this method were found to closely correlate with short chain fatty acid concentrations of cheese as determined by gas chromatography.Item Open Access Effect of route of administration of lasalocid on response of young dairy calves(Kansas Agricultural Experiment Station, 2012-09-20) Pruitt, S.D.; Morrill, J.L.; Nagaraja, Tiruvoor G.; Anderson, N.V.; Reddy, P.G.; tnagarajForty newborn bull calves were assigned to one of four feeding groups. The feeds either contained lasalocid in milk (M), prestarter (PS), and starter (S); lasalocid in PS and S; lasalocid in S only; or no lasalocid. Calves were fed M at 8% of birth weight (bw) daily and offered PS to a maximum of 0.5 lb daily. When 0.5 lb of PS was consumed in one day the calves were fed M at 4% of bw daily. They were weaned when they consumed dry feed at the rate of 1.3% of bw. Daily feed intake and weekly weight gains of calves were evaluated. Blood serum samples were used to evaluate blood metabolites at wk 4, 8, and 12. We concluded that lasalocid in M, PS, and S supported greater feed efficiency and allowed earlier weaning with less animal variation than when lasalocid was delivered in PS and S, only in S, or not at all.Item Open Access Bovine recombinant interleukin-2 enhances resistance to bovine herpesvirus-1: Dose response trial(Kansas Agricultural Experiment Station, 2012-09-20) Reddy, P.G.; Blecha, Frank; Morrill, J.L.; Minocha, H.C.Twenty-five calves were allotted to five groups: controls that did not receive bovine recombinant interleukin-2 (rIL-2) and four groups that received 5 daily injections of rIL-2 at 11.4, 1.1,0.11, or 0.0 II µg/lb/day. On day 0 of the experiment, all calves received bovine herpesvirus-I (BHV-1) vaccine and the first of the 5 daily injections of bovine rIL-2. All calves were infected with BHV-Ion day 21 of the experiment. Calves treated with 11.4 µg /Ib/day had elevated rectal temperatures and mild diarrhea during administration of rIL2. All other calves were normal. Compared to control calves, those treated with 11.4, 1.1, and 0.11 µg /Ib/day had higher (P<0.05) serum antibody titers to BHV-I and following challenge lower (P<0.05) BRV-1 titers in nasal secretions. Additionally, clinical disease as evidenced by nasal and ocular discharge was less severe. Cytotoxic responses against BHV-I-infected bovine kidney cells were increased (P<0.05) in calves treated with rIL-2 in a dose dependent manner. These data suggest that bovine rIL-2 at doses of 0.11 to 1.1 µg/Ib/day for 5 days may enhance immunity against BHV-I without causing adverse side effects.Item Open Access Early postpartum luteal function after treatment with progestin and(or) gonadotropin-releasing hormone in dairy cattle(Kansas Agricultural Experiment Station, 2012-09-20) Mee, M.O.; Stevenson, Jeffrey S.; jssProgestin (Norgestomet®) and(or) repeated low-dose infusions of GnRH (Cystorelin@) influenced the lifespan of the first corpus luteum after an induced ovulation. Holstein cows (n=32) were assigned at calving to four groups. Cows were treated with blank ear implants (days 2 to 9 after calving) and saline infusion (48 hr on days 10 arid II), progestin ear implants and saline infusion, blank implants and GnRH infusion, or progestin implants and GnRH infusion prior to a GnRH-induced ovulation (day 12). Four primiparous and four multiparous cows were assigned to each treatment. Fewer cows treated with progestin/GnRH ovulated in response to the GnRH challenge. However, short cycles (<17 days in duration) were prevented in all cows (n= 16) treated with progestin. In addition, all multiparous cows treated with blank implants and GnRH infusion had normal cycles. Results of this study suggested that progestin and GnRH may have altered follicular development, thereby preventing the short-lived corpus luteum and inducing a normal estrous cycle as cows overcame anestrus early postpartum.Item Open Access Milking management clinics(Kansas Agricultural Experiment Station, 2012-09-20) Dunham, James R.; Call, Edward P.Thirty Milking Management Clinics have been conducted at various on-farm locations. The clinics have demonstrated that good milking techniques can result in an additional 1891 lb milk yield/cow in a 10-mo lactation and an increased milk flow rate of 0.9 lb/min. Additional demonstrations include: I) teat dipping techniques, 2) proper sanitation programs, 3) antibiotic sensitivity culturing, 4) residue avoidance programs, 5) dry cow treatment techniques, and 6) milking equipment evaluation.Item Open Access Quality milk: A veterinarian's viewpoint(Kansas Agricultural Experiment Station, 2012-09-20) Reid, D.A.I would like to thank the organizers of this program for the opportunity to speak to you today on a subject that I feel is of the utmost importance to the dairy industry in the U.S. The problem to which I am referring is not the current devastating drought that has affected many of the dairy-producing areas in our country, but rather the repercussions of the dairy industry's inability to market a wholesome uncontaminated product that is viewed as such by a majority of the consumers in the U.S. I am sure that most of us here can remember the problems that occurred several years ago with contaminated Tylenol products that reached various market areas in the U.S. With the recent revelations that approximately 70% of the milk samples in several metropolitan areas, including Boston and Seattle, were contaminated with sulfamethazine, I fear that we in the dairy industry also could be faced with much more adverse publicity than what we have seen in the recent past. There has been at least one segment on 60 Minutes dealing with the potential contamination of milk products, along with articles in the Wall Street Journal. This publicity is definitely not what the dairy industry needs today. Currently, what publicity has been generated has not shaken the confidence that American consumers have in dairy products as a source of wholesome, uncontaminated, nutritional components of their diet. However, those of us that are involved in the dairy industry need to realize the potential devastation that could occur to our complete marketing system, if adulterated, contaminated milk is not removed from the market place.Item Open Access Animal drugs and the milk supply(Kansas Agricultural Experiment Station, 2012-09-20) Wilson, R.W.The makers of the laws, rules, and regulations governing the production and processing of milk have recognized that milk is the primary diet of the very young and old. This fact mandates that it should be produced and processed in a manner to protect and maintain it in a pure, safe, and unadulterated condition. To determine adulteration of any milk product, one must first understand the legal definition of that product. In general, milk is defined as "the lacteal secretion of healthy cows that is practically free from colostrum." Anything that alters the product from the intent of this definition constitutes adulteration.Item Open Access Managing the high-producing herd. III. Producing high quality milk(Kansas Agricultural Experiment Station, 2012-09-20) Shirley, John E.Progress in the dairy industry over the past 30 yr can be defined as a movement toward fewer farms, more cows per farm, fewer total cows, more milk per cow, a gradual decline in total annual milk production from 1950 through 1975 followed by a sharp increase through 1985, a decrease in per capita consumption, and an increase in milk quality.Item Open Access Double inseminations and treatment of repeat breeders with gonadotropin-releasing hormone(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; Call, Edward P.; Scoby, R.K.; Phatak, A.P.; jssAn experiment was conducted in one Kansas and five California dairy herds to determine if double inseminations with and without treatment with 100 µg gonadotropinreleasing hormone (GnRH) would improve conception rates of repeat-breeding dairy cattle (n=723). Both lactating cows and virgin dairy heifers were assigned randomly to treatments as repeat breeders, if they had failed to conceive to at least two previous services. Cows inseminated once and treated with GnRH had the best conception rates (41%), which were higher (P<.OI) than those of cows inseminated once without GnRH treatment (32%) and higher (P<.OI) than those of cows inseminated twice without treatment with GnRH (33%). Cattle bred twice that received the GnRH treatment had intermediate rates (37%). We conclude that treatment of repeat breeders with GnRH at the time of insemination (only one service given according to the am-pm, pm-am rule) improved conception rates.Item Open Access Timing of parturition in dairy cattle(Kansas Agricultural Experiment Station, 2012-09-20) Stevenson, Jeffrey S.; jssA recent survey of calvings of dairy heifers and cows revealed that fall calvings occurred in a nonrandom pattern. The survey was conducted in a large 5,000-cow herd in which pregnant females were watched 24 hr/day. Fewer (P<.005) calves (42%) were born during the night-time hours of darkness (6 p.m. to 6 a.m.) than during daylight hours (58%). The time of day when calving occurred was unrelated to the duration of pregnancy or to any of the climatic variables measured, including daily temperatures (highs or lows), barometric pressure, relative humidity, precipitation, average wind velocity, or percentage of sunshine. Although some reports and popular opinion have suggested that time of calving might be influenced partly by prevailing weather conditions, our data fail to support this notion. We are unable to explain the observed nonrandom pattern of calving, except that it might be influenced by other management routines on the farm.
